Neurological stimulation may be applied to specifically targeted nerve tissue in the spinal cord or a particular identified peripheral nerve to treat regions of the body affected by chronic pain from a variety of etiologies. According to one technique, a set of efficacious neurological stimulation parameters are determined, the set of parameters is entered into a stimulation system, and the stimulation system is used to electrically or chemically stimulate the specifically targeted nerve tissue in the spinal cord or particular identified peripheral nerve according to the set of stimulation parameters.
For electrical stimulation, typically, an implanted pulse generator transmits a pulse of electrical energy to an implanted electrical stimulation lead according to the set of stimulation parameters and, in response to the pulse, the electrodes of the implanted stimulation lead deliver the electrical energy to the specifically targeted nerve tissue in the spinal cord or particular identified peripheral nerve. The electrical energy stimulates the specifically targeted nerve tissue in the spinal cord or particular identified peripheral nerve to cause a subjective sensation of numbness or tingling in the affected region of the body, known as “paresthesia,” which masks or otherwise relieves pain in the affected region. For example, the electrodes may be located external to the dura adjacent the specifically targeted nerve tissue in the spinal cord that is to be stimulated. The electrodes typically must be precisely positioned based on the location of the specifically targeted nerve tissue in the spinal cord or particular identified peripheral nerve.
Alternatively, for chemical stimulation, typically, an implantable drug pump transmits a pulse of medication through an infusion catheter according to the set of stimulation parameters and, in response to the pulse, infusion ports of the implanted infusion catheter deliver the medication to the specifically targeted nerve tissue in the spinal cord or particular identified peripheral nerve. The medication stimulates the specifically targeted nerve tissue in the spinal cord or particular identified peripheral nerve to mask or otherwise relieve pain in the affected region of the body. The infusion ports typically must be precisely positioned based on the location of the specifically targeted nerve tissue in the spinal cord or particular peripheral nerve that is to be stimulated.
Of course, in many cases, chronic pain may be intractable other than through highly invasive surgical procedures. For example, for chronic pain in the low back area associated with a herniated disc, a discectomy or other radical surgery may be required for adequate pain relief. However, such highly invasive surgical procedures involve a host of undesirable consequences. These may include the significant cost of the surgery itself, the risk of paralysis or death due to complications during surgery, the trauma to the skin, muscles, nerves, and associated anatomical structures and the resulting scarring, pain, and discomfort that naturally results from the surgery, the significant rehabilitation time and associated costs following the surgery, and other consequences. Perhaps worse, such highly invasive surgical procedures often do not even completely suppress the chronic pain for which they were indicated.